1. Field of the Invention
The preferred embodiments of the present invention relate, inter alia, to a motorcycle equipped with an air cleaner.
2. Description of the Related Art
The following description sets forth the inventor's knowledge of related art and problems therein and should not be construed as an admission of knowledge in the prior art.
Conventionally, there is known a motorcycle in which a pair of right and left frames extending rearward from a head pipe are provided and at least a part of an air cleaner is disposed between both the frames (see, e.g., Japanese Unexamined Laid-open Patent Publication No. S63-145189 (hereinafter referred to as “Patent Document 1”) and Japanese Patent Publication No. 3701716 (hereinafter referred to as “Patent Document 2”). The air cleaner includes an air cleaner case and an air filter element disposed in the air cleaner case.
Although the aforementioned Patent Documents 1 and 2 do not clearly describe how the air filter element of the air cleaner is disposed, in a state in which at least a part of the air cleaner is disposed between the right and left frames, if the air filter element is disposed so as to divide the inner space of the air cleaner case into an upper space and a lower space, the following problems will occur.
An air cleaner is configured to remove foreign matters, such as, e.g., grit or dust (hereinafter simply referred to as “dust” or “foreign matters”) in air by passing air through the air filter element. Therefore, it is essential to assuredly prevent the air from bypassing the air filter element, which in turn requires assured sealing of the peripheral edge of the air filter element. However, as shown in FIG. 10, in a state in which an air cleaner case 101 is disposed between a pair of right and left frames 200 and 200, if a seal section 103 for sealing an air filter element 102 is disposed between the frames 200 and 200, the passage area of an air flow 300 mainly flowing generally vertically in the air cleaner case 101 becomes narrow at the inner side of the seal section 103. Such a small passage area of the air flow 300 in the air cleaner case 101 may sometimes cause insufficient intake volume of air to be supplied to an engine at the time of, e.g., a sudden opening operation of a throttle.
The description herein of advantages and disadvantages of various features, embodiments, methods, and apparatus disclosed in other publications is in no way intended to limit the present invention. For example, certain features of the preferred embodiments of the invention may be capable of overcoming certain disadvantages and/or providing certain advantages, such as, e.g., disadvantages and/or advantages discussed herein, while retaining some or all of the features, embodiments, methods, and apparatus disclosed therein.